Personal computers, now as ubiquitous as typewriters, are direct descendants
of the LINC, an invention made some two decades ago, at the close of the
paleocomputing era. In the early 1960's, digital computers were accorded
the reverence of religious totems. Massive machines engendered a mystique
that daunted even the most adventurous biomedical researchers. It was
an age when computers were untouchable, except through the ministrations
of computer acolytes; a time when programs, once relinquished to the computer
center, would be run and returned in about as long as it took a suit to
be cleaned (special rush jobs -- 24-hour service); when computers resided
in large glassed-in sanctuaries, with signs warning "Do Not Enter."
In short, a time of hands off. Only the privileged priestly caste -- designers,
operators, system programmers -- could gain direct access to a digital
computer, and they understood what the others were missing. Computer economics
encouraged the status quo. An hour on the IBM 7090, a common large commercial
machine, circa 1960 (some of today's micros are as powerful), cost $100
or more. The image of programmers pondering an elusive bug at such rates
could turn any cost-conscious administrator green.

The computer landscape was almost completely dominated by IBM
megaliths. With about 85 percent of the computer market, they ignored
what came to be called "minicomputers." With its investment
in large computers such as the 7094, and the introduction of the 360 series
machine, IBM had decided to push large "systems" which were
wildly expensive for most laboratory applications. Perhaps most importantly,
these systems were simply inappropriate for most laboratory uses. Small
companies like Digital Equipment Corporation (DEC) sold digital equipment
for the lab, but they were building blocks not computers.

In this environment, two groups at MIT came up with different approaches
to encourage direct access. The first, called "time-sharing,"
was intended to create the illusion for a number of users that each was
in control of a large machine -- in the first experiment, an IBM 7090.
The basic idea was to slice a second into, say, 20 slivers, so that each
of 20 users would be addressed in turn every second for 50 milliseconds.
In such a system, a programmer would be charged for three minutes of computer
time every hour. This approach allowed programmers to find design errors
and to debug their programs much more efficiently than with the old "batch"
mode of access.

About 10 miles away from the main campus, at MIT's
Lincoln Laboratory, in Lexington, Massachusetts, a different approach
emerged. While participating in designing two highly advanced computers,
TX-0 and TX-2, under Navy sponsorship, Wesley Clark realized that time
sharing was not the only solution to the problem of direct access. Having
designed a special-purpose machine for brain research, Clark understood
how computers could transform the biomedical laboratory. Direct access
was crucial, but for Clark, that also meant complete "ownership"
of the machine. As he put it, "a computer should be just another
piece of lab equipment." In 1961 this notion was heretical. Computers
were too expensive and veiled in mystery for most biomedical researchers.
Even at MIT's prestigious neighbor, Harvard, advanced experiment control
meant a rack of clicking relays, clumsy to change and seriously limited
in interpretive power.

Clark, who had contributed substantially to the development of the large
TX-0 and TX-2 computers, had seen small but inconvenient CDC-160's used
in a few labs. He proposed building a relatively inexpensive, general-purpose
computer that could be controlled easily by biomedical researchers, but
his suggestions were met with indifference by Lincoln Lab's management.
The Air Force was paying most of the bills for operational support and
biomedical applications were not high on the agenda. However, with encouragement
and support by William Papian, the group leader, Clark continued to work
on his idea for a small computer. Papian, one of the developers of ferrite
core memories, a landmark in computer design, understood the implications
of Clark's ideas. Despite a lukewarm reaction from Fred Frick, director
of division 6, Clark disappeared from the lab for about 3 weeks in 1961,
and returned with a complete design for a small computer, with characteristics
that marketing representatives would later call "user friendly."

Clark's computer was designed to satisfy four basic criteria: easy to
program, easy to communicate with while in operation, easy to maintain,
and able to process biotechnical signals directly. No computer in the
early 1960's could come close to fulfilling those objectives. Later, Clark
added two shrewd criteria: it could not be too high to see over, and it
must cost at most $25,000, the amount a lab director could spend without
higher-level approval. The guideline for the height of the machine, which
at first seems only whimsical, indicated Clark's belief that a machine
should not intimidate its owner -- no awe-inspiring Golem for Clark.
Despite increasing pressure from Frick to support defense-related work
at Lincoln Lab, Bill Papian and Wes Clark were determined to build a prototype
machine -- a concrete test of Clark's design. Rather than designing new
circuits, Clark decided to use modules manufactured by DEC, a company
founded by Kenneth Olsen, who once had worked for Bill Papian at Lincoln
Lab. DEC modules, components of a kind of electronic erector set, were
in fact based on the digital circuits of the TX-2. Although the packaging
was new, the circuits were familiar to Clark and his associates. So, in
1962, using off-the-shelf DEC modules, Clark and his associates put together
a working computer. With a bow to Lincoln Lab and a pun on the feature
linking the user closely to the machine, they dubbed the computer "LINC."